1. Field of the Invention
This invention relates to a method and apparatus for vacuum processing. More particularly, the present invention relates to a method and apparatus for vacuum processing which is suitable for controlling a sample such as a semiconductor device substrate to different temperatures and vacuum processing the sample.
2. Description of the Prior Art
As disclosed in, for example, Japanese Patent Laid-Open No. 76876/1984, a conventional technology for vacuum-processing a sample by controlling it to different temperatures is such that an object (hereinafter referred to as a "substrate") to be etched is placed on an electrode disposed in a vacuum vessel, a reactive gas is introduced into the vacuum vessel, a voltage is applied to the electrode so as to generate gas discharge and the substrate is etched by this discharge gas at two or more different electrode temperatures.
In the prior art technology described above, a substrate temperature (to 60.degree. C. in this prior art technology) is raised in view of the etching selection ratio of MoSi.sub.2 to a resist and of producibility when an MoSi.sub.2 film is etched, and the substrate temperature (to 30.degree. C. in this prior art technology) is lowered in view of over-etching. In this prior art technology, the electrode is divided into an electrode on a high temperature side and another on a low temperature side. Etching of the substrate is carried out on the higher temperature electrode side, and after this etching, the substrate is transferred to the lower temperature electrode, and over-etching of the substrate is carried out. Alternatively, only one electrode is provided and the electrode temperature can be changed to high and low temperatures while the substrate is kept placed on the same electrode. The substrate temperature is raised to a high temperature to conduct its etching during processing and is lowered to achieve over-etching of the substrate after the etching.